diff --git a/include/winnt.h b/include/winnt.h
index 7ac470324eb..4489e93e188 100644
--- a/include/winnt.h
+++ b/include/winnt.h
@@ -282,7 +282,9 @@ extern "C" {
 #if defined(_MSC_VER)
 # define C_ASSERT(e) typedef char __C_ASSERT__[(e)?1:-1]
 #elif defined(__GNUC__) 
-# define C_ASSERT(e) extern char __C_ASSERT__[(e)?1:-1]
+# define C_ASSERT(e) extern char __C_ASSERT__[(e)?1:-1] __attribute__((unused))
+#else
+# define C_ASSERT(e)
 #endif
 
 /* Eliminate Microsoft C/C++ compiler warning 4715 */